/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2000 by Cisco Systems, Inc.  All rights reserved.
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * This file contains CRC-32C code use to verify
 * iSCSI HeaderDigests and DataDigests.
 */

#include <sys/types.h>	/* standard types */
#include "iscsi.h"	/* contains prototypes */
#include <hd_crc.h>

/*
 * This is the CRC-32C table
 * Generated with:
 * width = 32 bits
 * poly = 0x1EDC6F41
 * reflect input bytes = true
 * reflect output bytes = true
 */

uint32_t iscsi_crc32c_table[256] =
{
	0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
	0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
	0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
	0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
	0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
	0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
	0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
	0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
	0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
	0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
	0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
	0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
	0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
	0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
	0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
	0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
	0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
	0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
	0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
	0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
	0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
	0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
	0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
	0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
	0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
	0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
	0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
	0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
	0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
	0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
	0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
	0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
	0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
	0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
	0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
	0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
	0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
	0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
	0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
	0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
	0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
	0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
	0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
	0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
	0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
	0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
	0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
	0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
	0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
	0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
	0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
	0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
	0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
	0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
	0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
	0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
	0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
	0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
	0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
	0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
	0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
	0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
	0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
	0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351
};

/*
 * -1 - uninitialized
 * 0  - applicable
 * others - NA
 */
static int iscsi_crc32_hd = -1;

/*
 * iscsi_crc32c - Steps through buffer one byte at at time, calculates
 * reflected crc using table.
 */
uint32_t
iscsi_crc32c(void *address, unsigned long length)
{
	uint8_t *buffer = address;
	uint32_t crc = 0xffffffff, result;
#ifdef _BIG_ENDIAN
	uint8_t byte0, byte1, byte2, byte3;
#endif

	if (iscsi_crc32_hd == -1) {
		if (hd_crc32_avail((uint32_t *)iscsi_crc32c_table) == B_TRUE) {
			iscsi_crc32_hd = 0;
		} else {
			iscsi_crc32_hd = 1;
		}
	}
	if (iscsi_crc32_hd == 0)
		return (HW_CRC32(buffer, length, crc));

	ASSERT(address != NULL);

	while (length--) {
		crc = iscsi_crc32c_table[(crc ^ *buffer++) & 0xFFL] ^
		    (crc >> 8);
	}
	result = crc ^ 0xffffffff;

#ifdef	_BIG_ENDIAN
	byte0 = (uint8_t)(result & 0xFF);
	byte1 = (uint8_t)((result >> 8) & 0xFF);
	byte2 = (uint8_t)((result >> 16) & 0xFF);
	byte3 = (uint8_t)((result >> 24) & 0xFF);
	result = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3);
#endif	/* _BIG_ENDIAN */

	return (result);
}


/*
 * iscsi_crc32c_continued - Continues stepping through buffer one
 * byte at at time, calculates reflected crc using table.
 */
uint32_t
iscsi_crc32c_continued(void *address, unsigned long length, uint32_t crc)
{
	uint8_t *buffer = address;
	uint32_t result;
#ifdef	_BIG_ENDIAN
	uint8_t byte0, byte1, byte2, byte3;
#endif

	if (iscsi_crc32_hd == -1) {
		if (hd_crc32_avail((uint32_t *)iscsi_crc32c_table) == B_TRUE) {
			iscsi_crc32_hd = 0;
		} else {
			iscsi_crc32_hd = 1;
		}
	}
	if (iscsi_crc32_hd == 0)
		return (HW_CRC32_CONT(buffer, length, crc));

	ASSERT(address != NULL);

#ifdef	_BIG_ENDIAN
	byte0 = (uint8_t)((crc >> 24) & 0xFF);
	byte1 = (uint8_t)((crc >> 16) & 0xFF);
	byte2 = (uint8_t)((crc >> 8) & 0xFF);
	byte3 = (uint8_t)(crc & 0xFF);
	crc = ((byte3 << 24) | (byte2 << 16) | (byte1 << 8) | byte0);
#endif

	crc = crc ^ 0xffffffff;
	while (length--) {
		crc = iscsi_crc32c_table[(crc ^ *buffer++) & 0xFFL] ^
		    (crc >> 8);
	}
	result = crc ^ 0xffffffff;

#ifdef	_BIG_ENDIAN
	byte0 = (uint8_t)(result & 0xFF);
	byte1 = (uint8_t)((result >> 8) & 0xFF);
	byte2 = (uint8_t)((result >> 16) & 0xFF);
	byte3 = (uint8_t)((result >> 24) & 0xFF);
	result = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3);
#endif
	return (result);
}
